Rational Synthesis And Optical Functional Modulation Of Binary Organic Charge Transfer Alloys

Compared to single-component organic crystals,multicomponent organic crystals made of two or moreπ-conjugated molecules usually exhibit more superior photoelectric properties.Among them,organic alloys or charge-transfer（CT）cocrystals have attracted extensive attention and interest due to easy tailoring of their structures and functions.This thesis aims to integrate organic alloys with CT cocrystals to construct binary organic CT alloys with adjustable compositions and functions.In this thesis,the frequently usedπ-conjugated compounds perylene（Pe）and9,10-dicyanoanthracene（DCA）are specifically selected as an electron donor and an acceptor,respectively.Using the good/poor solvent diffusion-induced co-assembly method,two types of organic CT alloy assemblies with tunable luminescence and dimensions,namely one-dimensional（1D）（DCA）_1-x（Pe）_xmicroribbons and two-dimensional（2D）（Pe）_1-y（DCA）_ynanosheets,were successfully developed.And then,the photon transmission characteristics of these two types of alloy assemblies were respectively studied.1.A series of color-tunable light-harvesting 1D（DCA）_1-x（Pe）_x（0≤x≤10%）CT alloy microribbons were controlled prepared by simply adjusting the molar ratio of Pe and DCA via the good/poor solvent diffusion-induced co-assembly method,in which DCA was used as the host matrix and a portion of Pe as the dopant.The spectrum analysis reveals that green emitting DCA acts as an energy donor,while red-emitting Pe-DCA binary CT complex with weakly-bound CT character acts as an energy acceptor,thus facilitating highly efficient energy transfer（ET）processes.Additionally,we have also studied the optical waveguide properties of these 1D alloy microribbons.Importantly,the controllable waveguide loss coefficient was realized by simply tailoring the stoichiometric ratio of the organic alloy assemblies.2.A series of color-tunable light-harvesting 2D（Pe）_1-y（DCA）_y（0≤y≤5%）CT alloy nanosheets were controlled synthesized by adjusting the molar ratio of DCA and Pe via the good/poor solvent diffusion-induced co-assembly method,in which DCA was used as the host matrix and a portion of Pe as the dopant.The spectrum analysis reveals that yellow-emittingα-Pe acts as an energy donor,while red-emitting Pe-DCA binary CT complex acts as an energy acceptor,thus facilitating highly efficient ET processes.In addition,we have also studied the optical waveguide properties of these 2D organic alloy nanosheets.By tailoring the stoichiometric ratio in the organic alloy assemblies,（Pe）_1-y（DCA）_ynanosheets exhibits the continuous waveguide conversion from isotropic to anisotropic photon transmission.